Syringe Assembly & Method for Accurate Dosing

Abstract

A method and apparatus for controlling and visually, audibly, and tactilely communicating the administration of discrete unit doses of material dispensed from a syringe through use of a modified plunger having a geometric profile corresponding to a unit dose. This profile engages with the syringe barrel in a manner that creates noise and vibration as each unit dose is administered. The profile may take the form of peaks and valleys or teeth. Alternatively, the plunger profile may be threaded and may include a channel along the plunger's longitudinal axis.

1 . An apparatus for controlling and visually and tactilely communicating the administration of discrete unit doses and fractional unit doses of material dispensed from a syringe, the apparatus comprising:
 a barrel having an interior and adapted to contain a liquid within said interior of the barrel, the barrel comprising a distal end, a proximal end, and a flange;   a plunger having an exterior and a longitudinal axis, said plunger configured to be inserted into the proximal end of the barrel and being moveable within the interior of said barrel such that liquid within the barrel is advanced and delivered from the distal end of the barrel when force is applied to the plunger, said plunger exterior comprising a unit dose geometry along the longitudinal axis of said plunger corresponding to a plurality of unit doses; and   a dosage limiting key wherein said dosage limiting key is placed at a desired point along the unit dose geometry to deliver a selected unit dose and wherein said dosage limiting key stops the advancement of the plunger when it contacts the flange, thereby preventing further delivery of liquid from the barrel and providing visual and tactile feedback with each administered unit dose or fractional unit dose of liquid.   
     
     
         2 . The apparatus of  claim 1  wherein the unit dose geometry corresponds to a plurality of unit doses and fractional unit doses of material. 
     
     
         3 . The apparatus of  claim 1  wherein the dosage limiting key further comprises a central through-hole sized to receive the plunger and at least one u-shaped recess extending from the through-hole and configured to engage with and clamp into the unit dose geometry. 
     
     
         4 . An apparatus for controlling and visually, audibly, and tactilely communicating the administration of discrete unit doses of material dispensed from a syringe, the apparatus comprising:
 a barrel having an interior and adapted to contain a liquid within said interior of the barrel, the barrel comprising a distal end, a proximal end, and an engagement element wherein said engagement element is comprised of a deformable receiving mechanism and a projecting element; and   a plunger having an exterior and a longitudinal axis, said plunger configured to be inserted into the proximal end of the barrel and being moveable within the interior of said barrel such that liquid within the barrel is advanced and delivered from the distal end of the barrel when force is applied to the plunger, said plunger exterior comprising a unit dose geometry along the longitudinal axis of said plunger corresponding to a plurality of unit doses of material;   wherein said unit dose geometry is comprised of at least one channel along the longitudinal axis of the plunger and a series of uniformly spaced threads about the plunger exterior such that the pitch of the threads corresponds to a desired unit dose of liquid; and   wherein the projecting element recurrently engages and disengages with each channel as the plunger is advanced within the barrel, said recurrent engagement creating visual, audible and tactile feedback with each administered unit dose.   
     
     
         5 . The apparatus of  claim 4  wherein the plunger has an outer circumference and wherein multiple channels are introduced along the longitudinal axis of the plunger and are spaced equidistantly about said outer circumference to provide visual, audible and tactile feedback for fractional unit doses. 
     
     
         6 . The apparatus of  claim 4  wherein the engagement element is molded within the interior of the barrel.